Pirate attacks worldwide increased in frequency and violence last year, with a total of 445 incidents reported compared with 370 in 2002, the ICC International Maritime Bureau reported this week.

This was the second highest number of attacks since the IMB Piracy Reporting Centre in Kuala Lumpur started compiling statistics in 1991. The highest number was 469 incidents in 2000.

The IMB's annual report, Piracy and Armed Robbery against Ships, said 21 seafarers were known to have been killed - compared with 10 the previous year - and 71 crew and passengers were listed as missing.

Although attacks in the Malacca Straits, one of the world's busiest sealanes, were up from 16 to 28, almost all of these incidents were in Indonesian waters. No attacks were reported in Malaysian waters during the last six months of the year.

Captain Pottengal Mukundan, Director of the IMB, said: "This remarkable result is undoubtedly due to vigilant patrols and constant operations by the relevant Malaysian authorities, particularly the Royal Malaysian Marine Police.

"The Malaysian success proves once again that when law enforcement agencies take these attacks seriously there will be a corresponding reduction in attacks. We call upon countries with piracy problems to give greater priority to policing their waters."

The number of attacks using guns rose to 100 from 68 in 2002 and hostages taken nearly doubled to 359 seafarers. Ships were boarded in 311 instances and a total of 19 ships were hijacked.

Indonesian waters continue to be the most piracy-prone, with 121 reported incidents in 2003, followed by Bangladesh with 58 attacks and Nigeria with 39. Attacks off Nigeria almost tripled compared with last year to 39, making Nigerian waters the most dangerous in Africa for attacks on shipping.

The report showed some new trends. Hijackings of merchant vessels and their cargoes eased last year. All hijackings reported were in two main categories - military-style operations by militant groups seeking to hold crew members for ransom to raise funds for their cause and attacks against soft targets such as tugs and barges.

Attacks on tankers rose to 22% of the total. Captain Mukundan commented: "That these ships carrying dangerous cargoes may fall temporarily under the control of unauthorized and unqualified individuals is a matter of concern, for both environmental and safety reasons."

The IMB also reported an increase in coordinated attacks involving several boats at once, especially in Indonesian waters of the Malacca Strait and around Bintan Island. The attackers approach a target ship from different directions and spray the superstructure with gunfire in an attempt to get her to stop